7E1G

Structure of MreB3 from Spiroplasma eriocheiris

Summary for 7E1G

• Entry DOI: 10.2210/pdb7e1g/pdb
• Related: 7E1C
• Descriptor: Cell shape-determining protein MreB, MAGNESIUM ION, PHOSPHOAMINOPHOSPHONIC ACID-ADENYLATE ESTER, ... (4 entities in total)
• Functional Keywords: cytoskeleton, actin homolog, structural protein
• Biological source: Spiroplasma eriocheiris
• Total number of polymer chains: 2
• Total formula weight: 79398.67

Authors

Takahashi, D.,Miyata, M.,Imada, K. (deposition date: 2021-02-01, release date: 2022-02-16, Last modification date: 2023-11-29)

Primary citation

Takahashi, D.,Fujiwara, I.,Sasajima, Y.,Narita, A.,Imada, K.,Miyata, M.
ATP-dependent polymerization dynamics of bacterial actin proteins involved in Spiroplasma swimming.
Open Biology, 12:220083-220083, 2022

PubMed Abstract: MreB is a bacterial protein belonging to the actin superfamily. This protein polymerizes into an antiparallel double-stranded filament that determines cell shape by maintaining cell wall synthesis. , a helical wall-less bacterium, has five MreB homologous (SpeMreB1-5) that probably contribute to swimming motility. Here, we investigated the structure, ATPase activity and polymerization dynamics of SpeMreB3 and SpeMreB5. SpeMreB3 polymerized into a double-stranded filament with possible antiparallel polarity, while SpeMreB5 formed sheets which contained the antiparallel filament, upon nucleotide binding. SpeMreB3 showed slow P release owing to the lack of an amino acid motif conserved in the catalytic centre of MreB family proteins. Our SpeMreB3 crystal structures and analyses of SpeMreB3 and SpeMreB5 variants showed that the amino acid motif probably plays a role in eliminating a nucleophilic water proton during ATP hydrolysis. Sedimentation assays suggest that SpeMreB3 has a lower polymerization activity than SpeMreB5, though their polymerization dynamics are qualitatively similar to those of other actin superfamily proteins, in which pre-ATP hydrolysis and post-P release states are unfavourable for them to remain as filaments.

PubMed: 36285441
DOI: 10.1098/rsob.220083

Experimental method

X-RAY DIFFRACTION (1.75 Å)